2 Stage Redaction of James?

R. P. Martin in his commentary on James [Word, 1988, pg. lxxiii], following P.H. Davids The Epistle of James [Eerdmans, 1982, pg. 12-13] and others have proposed a two stage redaction for the epistle of James. Davids explains that:

If one wishes to explain the apparent contradiction of fors, it will be necessary to come to some type of a two-level hypothesis for the composition of the work. This same hypothesis may also explain some of the curious divergeneces in vocabulary, some of the conflict between the very good Greek in places and Semitisms in others, and some of the apparent disjointedness between topics in the epistle...

The first stage is a series of Jewish Christian homilies, sayings, and maxims, many of which would have been composed in Greek by a person who spoke Aramaic as his mother tongue, while others may have been translations. The second stage is the compilation of an epistle by editing these pieces together into a whole. (12)

L.T. Johnson remains critical of this view. Johnson notes that, “all the usual criteria for positing a late dating for New Testament writings are absent… On the face of it, everything in the letter suggests an early dating rather than a late one.”[1] Also, Patrick Hartin has argued that:

An early date for this writing is required from the evidence noted..., namely, (1) the way the author refers to himself, expecting his hearers/readers to know his identity; (2) the closeness of the author to the heritage of Israel (he still sees himself as belonging to that world); (3) the use made of the Jesus traditions (prior to the appearance of the canonical gospels); (4) the closeness to the spirit and vision of Jesus; (5) the total lack of reference to the Gentiles in any form; and (6) the omission of any reference to the destruction of the Temple at Jerusalem.[2]

Some of these reasons may be objected to, especially 5 & 6, but otherwise these are particularly apt. Ultimately though, for reasons not readily apparent, Hartin joins Davids, Martin and co in accepting that the letter of James was composed after James' death by an amanuensis or scribe in the mid 60's. My conjecture is that if James was edited by a later redactor, the traces of this redaction are extraordinarily hard to detect and one could postulate that what the redactor has done is perhaps remove narrative sections from the epistle so as to make it more useful in a wider context. This would explain the awkward genre of James and the abrupt ending that has puzzled scholars for some time. Or that the letter has undergone literary revision, as proposed by F. F. Bruce.[3]

The question I have is, are there any contemporary Jacobean scholars who argue [not merely assert] against a two stage composition, or for a single stage writing? (Other than L.T. Johnson) -> [If Jim Darlack knows the answer, could he please email me references so that I may acquire such arguments and assess them. Thanx!] This is a pivotal piece of my argument concerning James 5:6. Once I have resolved this, one may begin to fully lay out the arguments concerning that text.

[1] L. T. Johnson “The Social World of James: Literary Analysis and Historical Reconstruction” in Brother of Jesus, Friend of God: Studies in the Letter of James (Eerdmans, 2004), pg. 110. Johnson notes the specific criteria as: “no institutional development, no sense of tradition as a deposit, no polemic against false teachers, no highly developed Christology, no delay of the parousia.”

[2] P. J. Hartin, James (Liturgical Press, 2003) pg. 24

[3] F. F. Bruce "The General Letters" in G. C. D. Howley (ed.) A New Testament Commentary London, 1969)